Exfo EXpert IPTV Test Tools (FTB-200v2) Uživatelský manuál stáhnout pdf (Strana 78)

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Glossary 

Perceptual Quality Metrics

Metric Description

MOS‐V VideoMOS,a1‐5scorethatconsiderstheeffectofthevideocodec,

framerate,packetlossdistributionandGoPstructureonviewingquality

MOS‐A1andMOS‐A2for2codecsthat

arepresentinsomestreams

AudioMOS,a1‐5scorethatconsiderstheeffectoftheaudiocodec,bit

rate,samplerateandpacketlossonviewingquality

MOS‐A1V Audio‐VideoMOS–a1‐5scorethatconsiderstheeffectofpicture&

audioqualityandaudio‐videosynchronizationonoveralluserexperience

VideoServiceTransmissionQuality

(VSTQ)

Transmissionquality,a0‐50codecindependentscoremeasuringthe

abilityoftheIPTVnetworktocarryreliablevideo

VideoServicePictureQuality(VSPQ) Picturequality,a0‐50scorethatconsiderstheeffectofthevideocodec,

framerate,packetlossdistributionandGoPstructure

GapVSPQ Picturequalityduring“good”periodswhenlittleornodegradationis

occurring

BurstVSPQ Picturequalityduring“bad”periodswhensignificantdegradationis

occurring

VideoServiceAudioQualityfor2

codecs(VSA1QandVSA2Q)



Audioquality,a0‐50scorethatconsiderstheeffectoftheaudiocodec,

bitrate,samplerateandpacketlossonviewingquality



VideoServiceMultimediaQuality

(VSMQ)

Multimedia(Audio‐Video)quality,a0‐50scorethatconsiderstheeffect

ofpicture&audioqualityandaudio‐videosynchronizationonoverall

userexperience

EstimatedPSNR(EPSNR) EstimatedPeakSignaltoNoiseRatio(PSNR)expressedindB.Thisisan

estimateofthedistortionthathasoccurredbetweenthesourcevideo

streamandtheoutputvideostream.

DegradationFactors Percentagedegradationinqualitydueto(eachof)Loss,Discard,Codec

type,Audio‐VideoSync,DelayandRecency.

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Exfo EXpert IPTV Test Tools (FTB-200v2) Uživatelský manuál Strana 78